In modern circumstances, it is difficult and expensive to train soldiers and military defense personnel in the effective use of high-powered rapid-fire machine guns, by simply allowing such individuals to practice using the actual guns with live ammunition. The ammunition rounds are expensive, for example costing up to five dollars per round. The cost of ammunition alone quickly multiplies when it is recognized that a typical machine gun is capable of firing hundreds of rounds per minute. Adequate space for a practice gunnery range may not be readily available. Significant costs are involved in transporting the personnel and the equipment to suitable remote locations where adequate gunnery practice can be performed. Safety is always a major consideration when live ammunition rounds are fired, both to military personnel involved in gunnery practice and to non-military personnel who may be adjacent to the gunnery range. It is difficult to instruct during a live ammunition training session due to the noise and safety considerations involved when others are involved in similar, close-by, live-ammunition practice activities. Furthermore, it may be difficult to vary the targets quickly at a live-ammunition gunnery range.
These problems and practical constraints are exacerbated when training individuals to shoot from a moving vehicle such as a helicopter. If live ammunition practice is attempted from a moving helicopter, a large space is required in order to maneuver the helicopter and to provide targets and adequate safety barriers, especially when multiple individuals are involved in similar simultaneous training exercises. As a result, live gun practice requires considerable space, and the cost of operating the helicopter greatly multiplies the overall training cost.
Because of these and other considerations, simulated weapon training programs have been developed for teaching purposes. Such training programs use imitation machine guns which closely simulate the sensational aspects and the mechanical and physical requirements of firing actual machine guns. Firing is simulated by reproducing effects which mirror the sensual perceptions associated with firing the actual machine gun. The environment and the targets are electronically displayed, allowing them to be more easily varied and to simulate movement of the targets and the machine gun. The trajectory of the simulated bullet fired is also calculated. In those cases where the simulated fired bullet emulates a tracer, the trajectory of that simulated bullet is also displayed in the surrounding environment.
For helicopter gun training, the imitation machine gun is mounted in an open door of an imitation portion of the helicopter fuselage. The environment and the targets are displayed outside of the open door. The portion of the imitation helicopter fuselage is moved or shaken in a manner similar to the movement of an actual helicopter in flight while the display of the surrounding environment and the targets are moved to simulate the flight path of the helicopter.
Simulated weapons training programs offer other benefits. Environments of remote areas of the world may be simulated, thereby providing training exposure to such environments prior to actually deploying the military personnel to those locales. The accuracy of the training program and the abilities of the individuals trained may be assessed. The accuracy in shooting, and the success of the training itself, is gauged by comparing the calculated, projected trajectory of the simulated bullets relative to the displayed targets. The number of simulated rounds fired may also be counted to evaluate the efficiency of the individual doing the shooting. Other factors can be evaluated from the vast amount of information available from such computer-based simulated weapons training programs.
Of course, to be effective for training purposes, it is necessary to create a realistic simulated environment and a realistic experience of firing the imitation machine gun. Such simulation is accomplished principally by multiple computer systems which are programmed to perform their specific simulation activities in coordination with each other. In the end, the capability of the simulated weapons training program to imitate the actual use of the actual machine gun in an actual environment is the ultimate measure of effective and successful training.
Individuals become accustomed to the imitation machine gun due to the amount of simulated training received. Because of the familiarity gained from training with the imitation machine gun, use of the imitation machine gun should be essentially the same as the use of the actual machine gun; otherwise, differences in functionality or performance create unexpected problems or difficulties when using the actual machine gun.
Accurate simulation of firing an actual machine gun involves duplicating the recoil or reactive impact from firing each ammunition round, duplicating the sound of the explosion of firing each round, and duplicating the flash of light created when the bullet exits the muzzle end of the barrel. The recoil impacts are simulated by a recoil simulation device which shakes the imitation machine gun. The sound of firing each round is duplicated by an audio speaker attached within or close to the imitation machine gun. However, duplicating the burst of light from a muzzle flash has proven somewhat problematic.
While light sources in the environment surrounding the imitation machine gun can be controlled to deliver momentary flashes of light, the light does not create the intensity and sensual effect as occurs with an actual machine gun when sighting along the barrel. The highest intensity of the muzzle flash occurs at the muzzle end of the barrel and dissipates from their into the environment, which is essentially the opposite sensation of the light intensity distribution when light sources in the surrounding environment attempt to duplicate the muzzle flash.
Realistic muzzle flash simulation is particularly important in training for night operations using an actual machine gun. At night, the machine gun operator typically wears night vision goggles. The intensity of the light of an actual muzzle flash has the effect of momentarily blanking the visual effects from the night vision goggles. The operator is essentially momentarily blinded by each actual muzzle flash. To be effective, they operator must become accustomed to the momentary blanking of the night vision goggles. The operator may become disoriented or at least distracted if the operator has not become accustomed to the momentary blanking effects in the night vision goggles. Delivering momentary flashes of light from light sources in the environment surrounding the imitation machine gun is not as effective in blanking the night vision goggles as when the burst of light is emitted from the muzzle of the actual machine gun.
One of the constraints in simulating a realistic muzzle flash is that the highest intensity from the muzzle flash should be at or near the muzzle end of the barrel of the imitation machine gun, in order to simulate accurately the intensity of light from an actual muzzle flash. The light sources used to simulate the muzzle flash should also attempt to replicate the high light intensity from an actual muzzle flash. While the high intensity light can be delivered from a variety of light sources, those light sources may be so large physically that they must be attached separately to the barrel. Extra components connected to the imitation machine gun can cause a lack of familiarity or awkwardness in the use of the actual machine gun. Extra components may create an expectation of a certain feel, appearance and operating style that are not present when using the actual machine gun, and those differences may lead to degraded performance of the user in actual circumstances. Suitable light sources should have the capability of delivering repeated momentary bursts of light, without residual light emission after each burst is completed. Residual light emission after the burst has the effect of prolonging the blanking effect in night vision goggles. Light sources using filaments have a tendency for residual light emission from the heated filament after the pulse of energy has terminated. Suitable light sources must also have the capability of repeated and reliable long-term use.